This invention relates to a noise filter for suppressing radiation noises or the like leaking from a signal transmission cable, such as an interface cable, connecting a computer body and terminal units respectively.
As shown in FIG. 7, the conventional interface cable 8 for connecting a computer body 6 and a terminal unit 7 functions as an antenna for noises leaking from the computer body 6, thereby causing useless radiation.
Hence, it has hitherto been carried out that the interface cable 8, as shown in the same drawing, perforates through a ring 11 of magnetic material, such as ferrite, to apply an inductance component to the cable as a whole, thereby suppressing the useless radiation.
The magnetic material ring 11, however, is free with respect to the cable 8 so as to be difficult to be fixed thereto. For example, as shown in FIG. 8, the cable 8 once circles the wall of ring 11 axially thereof to thereby fix the ring 11 to the cable 8. Such fixing method is not easy and takes much time.
Also, the magnetic material ring 11, which is externally mounted when in use, is prone to hitting a foreign object leading to breakage.
An object of the invention is to provide a noise filter which can extremely simply fixedly support a magnetic material core.
Another object of the invention is to provide a noise filter which can house the magnetic material core in an apparatus so as to protect that the core from being broken due to an external force.
Still another object of the invention is to provide a noise filter easy to assemble even when having a number of lines, and which need not be subjected to any particular insulating process.
These and other objects of the invention will become more apparent in the detailed description of the preferred and embodiments which follow.